


Breath of Life

by OnceABlueMoon



Category: Avatar: The Last Airbender
Genre: Alternate Universe - Fusion, Demons, Feminist Themes, Gen, Kimetsu no Yaiba Fusion, Podfic Welcome, Sexism, Swords, This is the answer, magic sword powers are cool okay, what if bending via swords was a real thing you ask
Language: English
Status: Completed
Published: 2020-07-01
Updated: 2020-07-01
Packaged: 2021-03-05 06:20:06
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,149
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25019917
Author URL: https://archiveofourown.org/users/OnceABlueMoon/pseuds/OnceABlueMoon
Summary: "I'm just saying," Sokka whines on top of the bison, "The whole thing about the Avatar bringing balance to the world is bullshit. What's being able to do all breaths gonna help Aang with? Murder demons? Sure, that'd bring balance, but I don't see him hacking off a head properly.""Yes, Sokka," Katara sighs, "You're a better swordsman than Aang. This is the nth time you're telling me this."Sokka huffs. "All I'm saying is that I havea point. Being able to hack off heads is more useful than having all breaths and not using them."He's right, though Katara doesn't want him to be. Objectively, her brother really is the most powerful person in their group. Though his breath doesn't fall within the most powerful breaths, the elemental ones, he is undeniably the best swordsman. Katara learned how to wield a sword at his knee, when no one else wanted to teach her. Katara can teach Aang the breath of water, but Sokka can teach Aang how to be a demon slayer.
Comments: 10
Kudos: 39





	Breath of Life

**Author's Note:**

> Disclaimer: I don't own avatar the last airbender.
> 
> This was written for kyou/jurosuke! I had lots of fun talking about how a fusion like this would be with them!

**Breath of Air**  
  
The breath of air acolytes have nearly forgotten their origin, for all they still practice their breath. They believe in pacifism, in a world that is just, in the power of a healthy, good mind.  
  
But nearly isn't _all_ forgotten, and their origin certainly hasn't forgotten _them_.

Aang’s good at the breath of air. The temple’s martial arts might seem strange to those from other temples, but Aang grew up with them. The breath feels natural in his lungs as he moves with the wooden swords as he makes his way through the kata. This isn’t about mimicking a fight, this is about mimicking the struggle of the spirit in a human body. These two things look very alike, but they aren’t the same. Violence doesn’t need to be inherent to human nature. 

This is what Aang believes, before they came. 

They come every year, and they test a group of disciples around the age of ten. For aptitude. What kind of aptitude, Aang doesn’t know, but he does know that he must take the test just as all the others have done before him.

They explain the process before they start. The man conducting the test, large, with a dark uniform on, speaks with a booming voice: ‘’We will watch you go through your forms. You’ll be sent away one by one until only one group remains. That group will get an additional test, and then a choice.’’ 

Aang blinks, cocking his head. ‘’What kind of choice?’’ 

The man looks up, a frown on his face. ‘’Whether you’ll stay here or come with us. Further information will be provided _after_ the test.’’ 

Aang doesn’t really know what to do with this. The man is a stark contrast, with his dark colours, amongst the yellow and orange of the monks around him. His manner too, is not something Aang is used to. It is… opposite. Like Earth to Air. There are scars on his face, and the sword at his side doesn’t seem to be made of wood. 

Aang wonders whether this man has seen violence. Whether his struggle of the spirit is one of overcoming his past battles. Whether he battles still, and what he has come to whisk the chosen away to. 

He shudders as he takes his place on the field amongst his fellow disciples, shifting into the first form. He looks at monk Gyatso, who is watching from the sidelines, but the man just nods encouragingly. That’s right. They have a choice. If Aang doesn’t want to, he doesn’t have to go to the place the man dressed in black came from. 

He breathes and moves through the forms, embodying the struggle of the spirit as they go against themselves, wooden sword in hand until it is soothed. The last move of the routine is putting the sword down. Aang moves like the wind, like a storm, like a spirit hidden within it. 

He moves on to the next round. One by one, the disciples are called into a room. When Aang enters, he sees the man in black and the monks surrounding a big table full of items. ‘’Choose,’’ the man in black says. 

Aang’s eyes stray over the items arrayed before him. There’s a baby rattle, jewellery, prayer beads, bowls of varying shapes and sizes. There are keys, there are locks, there are pills and things shiny and dull both. They’re all very interesting, but his eyes keep straying towards one item, so he picks that one. 

He picks the hanafuda earrings with the sunbeam on them. The monks surveying gasp. At first, Aang doesn’t get it, so he just stands there as their eyes widen. Then, he thinks he’s done something wrong, so he’s just about to put the earrings back neatly— maybe they’re fragile or something? Maybe they weren’t supposed to touch the item they picked?— when the large, scarred hand of the man in black curls around his, closing his fingers around the earrings. ‘’They’re yours.’’ He says. 

Okay…? 

‘’Thank you,’’ Aang says, not knowing what to say otherwise. He wants to fly up the roof, hide there with his wooden sword pressed against his side, in the wind, free and wild. 

The man shakes his head. ‘’You don’t understand. It has always _been_ yours. You’re the Avatar, the user of all breaths, the one who reincarnates amongst the four elemental breaths and helps us in the fight against the dark.’’ 

Hesitantly, Aang takes his hand back, though he doesn’t let go of the earrings. ‘’Fight?’’ 

The man nods. ‘’ _Your_ fight against the dark. You might not see them, but there are monsters that bump in the night. You help the balance in the world by giving them peace.’’ 

‘’I can do that?’’ Aang asks, with big eyes. 

The man nods solemnly. ‘’You can, if you come with us.’’ 

Aang agrees enthusiastically. When monk Gyatso comes to say goodbye, his eyes are sad, but surely that must just be because his favourite disciple is going away. 

* * *

He is horrified when he finds out what goes bump in the night. Demons are the very definition of what ought to terrify humanity: monsters, that get stronger on the taste of human flesh and blood. Hunters, who prey upon them at night. The man in black slays the ones that assault them on their way to their destination.

Demons are terror personified, and yet... And yet, he can only see humanity, as exaggerated, as darkened as it is in these creatures called demons. The moment the man in black ends their lives, he sees it in their eyes, the desire, above all, to live, to be free, as light and airy as the air itself. 

The man in black wipes the blood of his sword with the grass beneath them. Aang hurls in a bush. 

‘’Get used to it, kid.’’ Says the man, ‘’We’re demon slayers, this is what we do.’’ 

_Demon slayers,_ Aang thinks. Nobody told him he’d be a slayer. That’d he’d be expected to _kill_ in order to ‘give peace’. He hurls once more, and then, when the man in black’s back is turned, he runs, runs until he’s close enough to the herd of sky bisons that he can see his friend Appa. Until he climbs Appa’s back and _flees._

They fly, as far away as possible from the slayer, from the demons, from the corpses. They fly, until they’re caught up in a storm above the ocean, until they try to get down only to meet water, and a wave as large as the temple catches them. 

For a second, Aang thinks: I’m going to die. 

Then there is nothing. 

**Breath of Water**  
Katara's day goes a little like this:  
"I'm just saying," Sokka whines on top of the bison, "The whole thing about the Avatar bringing balance to the world is bullshit. What's being able to do all breaths gonna help Aang with? Murder demons? Sure, that'd bring balance, but I don't see _him_ hacking off a head properly."  
  
"Yes, Sokka," Katara sighs, "You're a better swordsman than Aang. This is the nth time you're telling me this."  
  
Sokka huffs. "All I'm saying is that I have _a point_. Being able to hack off heads is more useful than having all breaths and not using them."  
  
He's right, though Katara doesn't want him to be. Objectively, her brother really is the most powerful person in their group. Though his breath doesn't fall within the most powerful breaths, the elemental ones, he is undeniably the best swordsman. Katara learned how to wield a sword at his knee, when no one else wanted to teach her. Katara can teach Aang the breath of water, but Sokka can teach Aang how to be a demon slayer.  
  
It rankles. She's the one who split the iceberg in which he was found, after all.  
  
It's not that Katara doesn't love her brother, she does, truly! It's not that she doesn't want to see him thrive, the sword his element. It's just that she's had to fight for every inch of power she has, and Sokka... Sokka worked hard, but he _gets_ the sword in a way she doesn't. He got training. She didn't.  
  
Is he truly stronger than her, or is this inequality yet another result of the casual sexism so rife throughout her life?  
  
She can't match her sword against her brother's as long as she doesn't know which it is.  
  


* * *

Katara has wanted to fight ever since their mother was killed by a demon. She’d been small, but she witnessed the whole thing. It had been horrifying, and the only reason Katara hadn’t been eaten too was that the sun can up and reflected off the ice, killing the demon only an instant before his teeth could rip into her vulnerable throat. 

The memory of her just sitting there, in the corner of the igloo, frozen as her mother was eaten, stays with her the rest of her life. It becomes an integral part of her, that fear that froze her there, the anger in the wake of it. Anger at herself, for being unable to move. Anger at the demon, for eating her mother. Anger at her brother and her father, who were away on a hunting trip. Anger at the society that did not let her wield a sword as her brother did. Anger, because she _knows_ her mother could have defended herself, had she been able to wield a sword. 

What little she knows she learned from Sokka, but for all that he is an accomplished swordsman, he does not have the breath of water, he can’t teach her the ways of a breath he does not know. 

  
She forces Pakku to teach her. Where at the South pole women simply didn’t take up the sword, it’s far worse in the North. The women here don’t even wield knives, not even to skin seals. Women are too delicate for that kind of work, they tell her. She rages and rages like the very sea, every breath torn from her throat, no oxygen left as she is _drowning_ in her anger. 

Katara drowns in the memory of her mother, murdered on the floor. She wants to be more than that. She wants to be able to not only defend herself, but others too. Katara wants _strength._ Katara wants the breath of water.  
  
"You are a woman." Pakku says, "Reckless and irrational and waning with the moon."  
  
"I am like my element," she says, "I rage against cliffs that will be worn down in time. I am still water deep down, so much deeper than you see, I follow the moon for that is the gravity the water knows."  
  
Her sword form gets sharper, her blade deadlier. Pakku is forced to accept her as his best disciple.  
  
It still doesn't solve her problem, but it sure makes her stronger, and that is what Katara needs.  
  
Her brother gets beat up by the Kiyoshi warriors because he underestimates them. It does him great good, if you ask Katara.  
  
"Did I do that to you too?" He asks, later.  
  
She nods. "You did."  
  
"I'll try to do better."  
  
It's still no apology, but she thinks she can work with this.

Steel sings in her bones, just as the water within her tugs her towards the moon, push and pull, take and leave. Katara will take all the strength there is. It lives in her breath of water. 

  
**Breath of Earth  
**

Ever since she was small, Toph has heard humans. They’re a little like this: boom-boom-boom, an explosion within a chest, rhythmically working to keep the body going. The heart, or its sound. That is what humanity is to Toph. The rapid thud of a mortal heart racing towards its end, the fast and vivacious movement of a human life. 

‘’I can’t face demons without seeing their humanity,’’ Aang says to her one night, as they sit close to the fire. Toph basks in its warmth and snorts. 

‘’I’ve never had that problem.’’ 

Demons sound like monsters. Ever since she was young, she has heard the strange, sticky sounds they make. It’s the blood, dead and syrupy in their veins. The slow, irregular _thunk_ of a heart that no longer beats properly. 

It’s dead. Or as near dead as a moving body can still be. 

Toph’s never liked the sound of demons. 

* * *

The first time Toph touches steel, it’s because a merchant ripped her father off. She’s clothed in silk, has satin slippers on her feet, ebony hairpieces in her hair, but the ring around her finger is steel, no matter that her father thinks it’s silver. 

Sometimes she wonders which of the two of them is blind. 

She shucks her shoes off at the earliest opportunity and leaves to make her way through the garden, slipping away from her nanny. 

She breathes

It is then that she feels it. Something about the way the steel reverberates makes her pay attention. The more she focuses on the little bit of steel around her finger, the more obvious it becomes. For a second, she thinks she can feel the objects all around her without touching them, an echo location all on it’s own. 

It startles her, which makes her breath hitch, and all of a sudden, just as quickly as it came, the sensation is gone. Toph is back in the dark, only her touch, smell and hearing to guide her. 

She tries again. 

* * *

Her breathing is hard to hold steady at times, especially because she has to focus both on her breath and the steel around her finger, but slowly and surely she learns. 

Her parents call her weak, but Toph can echo until she knows their shapes, even better than if she could see, she’s sure. She knows when people lie, she can feel it in the stutter of their heartbeats. She can feel the badger-moles, huge and ancient, moving in the earth underneath them. 

And that’s discounting all she already could before— she knows for a fact that her skin is far more sensitive than anyone else’s, and no matter what anyone says, that’s not a sign of _daintiness._ Neither is her hearing, so sharp she can hear a pin drop a li away. 

Toph is strong, her movements sure and unwavering where her family hesitates around her every time. 

She wants to move boulders. She needs to be even stronger for that. 

She finds it in the sword. 

Then she moves _real_ boulders and anyone who dares imply she’s frail, that she’s _helpless,_ is getting one dropped on them. 

Toph sounds like tough, and that’s what she is. 

  
**Breath of Fire**  
  
What do you do when your father is an immortal monster that calls himself the Phoenix King?  
  
Fight him, of course, after your redemption arc.

* * *

The thing is, Zuko knows that war is _wrong_ when you do it the way his father does. Or maybe all war is wrong. He’s not very certain about all this, because there’s supposed to be honour in battle, but there’s not much honour in killing. Killing is a disgrace. It shows lack of restraint, lack of _control_ and if there is one thing he’s learned in the last few years he’s been a disciple of his uncle, it’s that breath of fire users _cannot lack control._ Not of their lives and the lives of their friends are dear to them. 

It’s just… Banishment is not easy. Rejection is not easy. Having a burn on your face that marks you as an incompetent breath user isn’t easy either, even when the mark was placed by a demon. The others in team Avatar don’t know that. Zuko doesn’t _want_ them to know that. 

After all, when people speak of family members that turned into demons, they cry. They cry and tell a story of how they rescued them by killing them. By giving them peace. Zuko doesn’t have that kind of story. Zuko just has a burn on his face and the fortune to get away with his life intact. 

* * *

Zuko was born struggling. His birth was long and hard, and his mother nearly died in childbirth. Even years later, he still hears about it.

‘’During your birth she laboured for nearly three days!’’ the nursemaid tells him as she rocks Azula, just over a year old, in her arms. ‘’Sweated something awful, her screams were audible all over the palace. Hard birth was that,’’ she says, with a sage nod.

Zuko just thinks his mother must have wanted him an awful lot then, to go through so much pain to get him.

The nursemaid doesn’t ask what Zuko thinks. She just says: ‘’Your sister, now, _that_ was an easy birth. The second, of course, but easier. Good sign, that.’’

In hindsight, this is an omen of what to come.

* * *

Zuko is four and has his first spark. His mother is proud, oh so proud, but father just frowns because his sister had her first spark two weeks earlier. Zuko doesn’t get what was wrong with that, because how cool is it that _his little sister_ can already start with the training? And now he can join her! She’s only two, but she’s obviously the best little sister in the entire world and nothing is ever going to change that. 

Using the breath of fire is traditional for the royal family of the fire nation. Demons are widely known to haunt the night, and it has always been the royal family’s job to protect them. They do so with fervour, and Zuko will do them proud. Or so his mother says. 

Zuko just thinks the spark is warm, and that is wonderful. 

* * *

What he doesn’t know, until years and years later, is that his father was ready to cast him off the castle walls for not having the breath. Perhaps that would have been a mercy, compared to what having the breath led to later in life. 

* * *

His mother is gone one day, and Zuko doesn’t really understand, but they say there was a virus, and it hit both his parents. His mom succumbed, his father survived. 

Father just can’t stand sunlight anymore. Zuko thinks nothing of it.

(The palace staff do, but what can one say when the monster that doesn’t sleep is listening day and night? What can one do, when uttering a word will get you eaten? 

The nation rejoices it’s leader survived. Inside the castle, the people shudder)

* * *

Zuko is good with swords. Incredible, in fact, wielding broadswords as an extension of his own body. It’s not enough. The spark isn’t bright enough in him. Even as he wields the breath of fire along with his blades, his sister has already mastered that and moved on to the breath of thunder. 

He tries to be proud of her, but it’s hard when she uses him for target practice. "Father doesn’t mind, you know,’’ she tells him, smiling meanly, ‘’You’ve always been so hard to teach, whereas I understand everything so easily. You’re nothing but a has-been, Zuzu. Have fun, playing with your swords. I’ll be out there, doing the _real_ work soon enough.’’ 

Father is going to let her hunt demons? This… This isn’t good. Father likes Azula, because she’s so quick when it comes to the breath, because she doesn’t hesitate to kill animals, because she’s everything that Zuko’s not. 

He is the heir, and she’s the spare, and Zuko’s afraid that one of these days, someone decides that they’d rather have _her_ as the heir and kill him. 

~~Like Father.~~

He needs to find a way to be valuable. Following Father into the war chamber seems the way to go. 

He speaks up during the meeting and finds out it really, really wasn’t. 

* * *

The first time he notices something is wrong about the Agni Kai is when he is informed of the time it will take place. 

‘’At midnight?!’’ 

Azula smiles like baring her teeth will go out of fashion. ‘’Oh, yes, at midnight.’’ 

‘’But Agni is the sun god! You can’t hold an Agni Kai at night!’’ 

‘’This one will be.’’ She knows something he doesn’t and she isn’t telling. ‘’Will you forfeit? You can still back out.’’ But there is a challenge in her eyes and Zuko isn’t backing down. Not this time. 

‘’The general was wrong, I’ll fight him, midnight or not.’’ 

(His opponent wasn’t the general)

* * *

At the Agni Kai, when Zuko is on his knees, begging for forgiveness, his father raises his hand and burns his shame onto Zuko’s face. He doesn’t use a sword to channel the fire, as is required in order to release it from the spirit. No, he does it with his bare hand. 

It’s a lot more personal that way. A lot more impossible too. 

Zuko, shellshocked in the aftermath, thinks of how the Agni Kai was at midnight. About the virus that meant his father couldn’t walk in the sun. About the sudden power he can wield bare-handed— like a demon. 

But he can’t be, right? He’s Father, the Firelord, the man who’s supposed to _protect_ their nation from the creatures of the night. He can’t be a demon, that’s preposterous! 

The knowing glint in his Uncle’s eyes when he takes Zuko away isn’t reassuring at all. 

Zuko’s been banished. Zuko knows too much. Zuko doesn’t want to _believe_ what he knows. 

He focuses on the goal he has been given: if he brings the Avatar with him, he’ll be let back into the folds of the fire nation.

* * *

‘’What does Father want with the Avatar?’’ 

‘’There is a demon infestation in the fire nation,’’ Uncle Iroh says, pouring tea into the cups. It sloshes over the edge as their ship is tossed about on the waves. ‘’I’m hoping the Avatar will clean it up.’’ 

Zuko doesn’t know how to reply to that. Doesn’t think he really wants to. There’s so much in that statement that makes him think of things he doesn’t want to think of. Of _the_ thing he doesn’t want to think about. 

Zuko is thirteen and just starting to understand the world. He just doesn’t like the picture it paints, so he covers it up for some more time. 

* * *

A long time passes. Zuko does things he deeply regrets. Going with his sister, going back to Father, leaving Uncle in a _prison._

There are also things he decidedly _doesn’t_ regret, even if he regrets them happening. Like being forced to come to terms with the fact that his father is a _monster,_ a _demon,_ and that Zuko still wants his approval because it’s Father. 

He wants to cry. _Why_ does he feel like this? _Why_ can’t it be enough that he knows that his mother loved him, was proud of all he did? That Uncle went with him? Protected him, even in banishment? Does… Does Uncle even love him anymore? 

Father doesn’t. But at least Zuko knows that particular love most likely wasn’t ever there, even if he wanted it desperately. 

He goes to visit his old nursemaid. She’s a woman he has mixed feelings about, but she takes one look at him and embraces him, court regulations be damned. ‘’Oh, my boy.’’ she whispers into his hair, ‘’You’re _never_ responsible for the pain of your parents, and neither are you for their deeds.’’ 

There are tears in the one eye that still has a working tear duct, but nobody sees them because they flow into her robes. 

* * *

The next morning, she is dead. There is no corpse in the casket. 

Zuko knows who ate her. 

* * *

He goes to confront his father and leaves devastated. He had suspected the fate of his mother, but he hadn’t _known,_ hadn’t heard his father _gloat_ of how she killed his grandfather in order to save Zuko’s head, of how his father ate her afterwards, devoured her flesh and bones in order to keep the secret. 

He screams and he screams and he screams. 

His father’s blood art apparently extends from fire to lightning, because it is this that he sends towards his son and Zuko… Zuko shifts his feet, raises his dao, and _redirects the flow of the lightning._

He leaves Father stunned in the throne room and goes to break Uncle out of prison. 

Uncle’s already gone. 

Joining team Avatar it is, then. 

There is no heir or spare in doing the right thing. There is only hard, no easy in the path towards a better world. Zuko knows all this, but his life has always been hard, always been filled with pain and hurt. But there is agency, in this choice. 

Zuko rolls his shoulders, sheats his dao and throws himself from one roof to the next, on his way to his next destination. 

It feels good, taking his power back.


End file.
